Séminaire exceptionnel – 09 juillet 2021 – 11h amphi

Point-particle simulations of complex turbulent dispersed flows

Cristian Marchioli – Univ. Udine, Italie

Particle transport and mixing in turbulent flows are fundamental to science as well as to technology. The simplest numerical framework to study the dynamical and statistical features of turbulent particle dispersion is based on the assumption that particles can be modeled as point-like spheres brought about by the flow. In spite of its simplicity, this framework has led to significant advancements in the study of particles-turbulence interactions, allowing the precise identification of the coherent structures responsible for particle sedimentation and re-entrainment in turbulent boundary layers. In this talk we examine two possible sources of bias in particle dispersion, which arise when particles are non-spherical (elongated) and may actively move within the fluid (motile). In particular, we present results relevant for particles suspended in environmental and wall-bounded turbulence, showing how particle motion, preferential concentration and accumulation in turbulent boundary layer can be modulated by elongation and by motility.